太赫兹阵列探测器响应度校准溯源研究

提出了一种太赫兹阵列探测器响应度校准溯源方法。首先,使用阵列探测器的每一像元对太赫兹辐照场中心进行逐一扫描,识别有效像元、死像元和过热像元,并对有效像元响应值进行归一化处理,获得阵列探测器的相对辐照度响应值。其次,使用中心像元对太赫兹辐照场进行扫描测量,扫描总面积大于太赫兹光斑尺寸,保证太赫兹功率被完整测量,获得中心像元与其他有效像元的太赫兹功率响应值。最后,用标准太赫兹功率计标定高莱功率计,扩展太赫兹功率校准量限,实现微瓦级太赫兹辐射功率测量溯源,用高莱功率计测得的太赫兹辐射源总功率对阵列探测器测得的积分响应值进行校准,得到阵列探测器辐照度响应绝对值。对探测器进行测量校准和不确定度分析,测得辐照度响应度的相对扩展不确定度为Urel=20%(k=2),测量结果可溯源至国家太赫兹辐射功率标准。

Calibration and Traceability of Responsivity for Terahertz Array Detector

A method for irradiance responsivity calibration and traceability of a terahertz array detector is proposed. Firstly, each pixel of the array detector is shift to scan the center of the terahertz irradiation field one by one, and then effective pixels, overheated pixels and dead pixels is discerned. The response of the effective pixels is normalize to obtain the relative irradiance response of the array detector. Secondly, the center pixel is used to measure the terahertz irradiation field. Make sure the scanning area larger than the terahertz spot size, so that the total power of the terahertz radiation is fully measured. The terahertz power response values of the central pixel and other effective pixels are obtained.Finally, a Golay Cell detector is calibrated with a standard terahertz power meter as reference, and then the traceable measurement of terahertz power is extended to microwatt-level. The integrated response value measured by the array detector is calibrated with the Golay Cell. And thus the absolute irradiance response of the array detector is obtained. The relative expanded uncertainty of the measured irradiance responsivity is 20% (k=2), and the measurement result can be traceable to the national terahertz radiant power standard.